/**
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2013, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
package ch.qos.logback.core.property;

import ch.qos.logback.core.PropertyDefinerBase;
import ch.qos.logback.core.util.OptionHelper;

import java.io.File;

/**
 * In conjunction with {@link ch.qos.logback.core.joran.action.PropertyAction} sets
 * the named variable to "true" if the file specified by {@link #setPath(String) path}
 * property exists, to "false" otherwise.
 *
 * @see #getPropertyValue()
 *
 * @author Ceki G&uuml;c&uuml;
 */
public class FileExistsPropertyDefiner extends PropertyDefinerBase {

  String path;

  public String getPath() {
    return path;
  }

  /**
   * Sets the path for the file to search for.
   *
   * @param path the file path
   */
  public void setPath(String path) {
    this.path = path;
  }

  /**
   * Returns "true" if the file specified by {@link #setPath(String) path} property exists.
   * Returns "false" otherwise.
   *
   * @return "true"|"false" depending on the existence of file
   */
  public String getPropertyValue() {
    if (OptionHelper.isEmpty(path)) {
      addError("The \"path\" property must be set.");
      return null;
    }

    File file = new File(path);
    return booleanAsStr(file.exists());
  }
}
